Universal Zincs
I just replaced my heat exchanger zincs. Which is what I think you are referring to. I didn't know these existed a month ago either, so I know how you feel. The zincs are located at the heat exchanger. If you look at your manual, you will notice a large nut underneath the exchanger. When you remove it you should see the zinc attached to it. The zinc and nut are actually one piece. If all you have is the nut, like i did, replace it. Go to west or boat us. they should have plenty of them. Cost: $8. If you are referring to the shaft zincs, well the location is self explanatory. How often to replace depends on weather you are on the dock, using shore power or on a mooring. Questions? dbousquet@aol.com